1. Field of the Invention
This invention relates to 3-alkyl-3-oxo-1-aminopropane-1,1-diphosphonic acids obtainable by diphosphonylation of oxonitriles, to water-soluble salts thereof, to a process for their production, to their use as microbistatic agents, and to microbistatic compositions containing them.
2. Statement of Related Art
1-Amino-1,1-diphosphonic acids corresponding to the following general formula ##STR3## in which A, B and C represent a liphatic, cycloaliphatic or aromatic hydrocarbon radicals, in addition to which B and C may additionally represent a hydrogen atom, are known from the prior art. They are prepared by reaction of nitriles with phosphorus trihalides and subsequent hydrolysis or alcoholysis (German Application No. 10 02 355), by reaction of nitriles with phosphorous acid (German Application No. 26 25 767), or by reaction of carboxylic acid amides with phosphorus trihalides in the presence of phosphorous acid and subsequent hydrolysis (German Application No. 19 58 123). Phosphonic acids corresponding to general formula (I) above are capable of complexing heavy metal ions and alkaline-earth metal ions. Accordingly, they are widely used as complexing agents and chelating agents for softening water, in the manufacture of detergents in the textile field and in paper making. In addition, German Application No. 10 02 355 mentions their use in pharmaceuticals and pesticides.
In addition, structurally related compounds corresponding to the following general formula ##STR4## which are also known as complexing agents, are known to be useful in the pharmaceutical field. In formula (II), B and C represent hydrogen or aliphatic or aromatic radicals in accordance with general formula (I) above while D is a C.sub.1 -C.sub.5 alkylene radical. German Patent Nos. 24 05 254 and 25 34 391 describe the use of compounds corresponding to general formula (II) and water-soluble salts thereof in the prophylaxis and therapeutic treatment of disorders of the calcium or phosphate metabolism in humans and animals.